Dental articulator



(No Model) FQPOURT. DENTAL ARTIGULATOR.

No. 582,731. Patented May 18, 1897;

/ll//7////7//A UNITED STATES PATENT FFICE.

FRANK FOURT, OF FAIRFIELD, IOIVA.

DENTAL ARTICU LATO R.

SPECIFICATION forming part of Letters Patent No. 582,731, dated May 18,1897.

Application filed February 5, 1896. Serial No. 578,134. (No model.)

To all whom it may concern:

Be it known that I, FRANK FOURT, a citizen of the United States,residing at Fairfield, in the county of Jefferson and State of Iowa,have invented an Improved Dental Articulator, of which the following isa specification.

My invention relates to dental articulators having upper and lowermembers hinged together; and it consists, first, of the construction ofthe hinged or jointed parts with rearwardly-extending ends and hingingor jointin g them together so their rearwardly-extending ends will, whenthe articulator is opened, come in contact and hold the memberssubstantially at right angles to each other, and the articulator willstand on the outer face of either member and be readily tilted from oneposition to the other without doubling up or falling over also, of animproved form of hinge or joint and of other improvements in the detailsof construction hereinafter set forth.

In the accompanying drawings, Figure 1 is a side elevation of thedevice. Fig. 2 is a plan view.- Fig. 3 is a bottom view, and Fig. 4 is adetail view.

In the drawings, A represents a body-piece, and B the upper-jaw piecesecured to said body-piece so as to have longitudinal adjustmentthereon.

0 represents a lower-jaw piece having upwardly-extending arms d, whichare hinged to the body-piece at e. The joint 6 is placed a sufficientdistance above the base of the lower-j aw piece to permit the upper-j awpiece to stand parallel with it and leave sufficient room between themfor the dentists models, which are not shown in the drawings.

The rear end 0 of the base of the lowerjaw piece is extended a littlebackward of the joint 6, and the rear end D of the body-piece isextended as far behind the joint e as it is above the base of thelower-jaw piece. By this arrangement the rear end of the bodypiece will,when the articulator is opened, come in contact with the rear end of thebase of the lower-jaw piece and will hold the upper and lower jaw piecesat substantially right angles to each other. The upper-jaw piece will beheld in a perpendicular position, while the rear end D of thebody-piece, which is preferably made broad and rectangular, will rest onthe table upon which the articulator may be standing and will helpsupport it in position.

Should the dentist desire to place the upper-jaw piece in a horizontalposition while the articulator is open to manipulate the model which maybe secured thereto or for any other purpose, all he has to do is to tipthe articulator over on its upper face. The faces of the body-piece andthe upperjaw piece, which is secured to it, being fiat and in alinementwith each other, will support the articulator firmly and hold thelower-jaw piece in a perpendicular position. In tipping the articulatorfrom one position to the other the upper edge of the rear end of thebody piece Will form the pivot or fulcrum, and the articulator maybereadily tipped from one position to the other without doubling up orfalling over.

In order to keep the upper face of the bodypiece in alinement with theface of upper-jaw piece and yet retain their longitudinal adj ustment, Iform a recess in the face of the inner end a of the body-piece and makethe end I) of the jaw-piece to fit this recess and fill it fiush withthe face of the body-piece. I also form a recessed slot bin the end I)of the jawpiece and pass a thumb-screw E up through a hole in therecessed part of the body-piece and also through the slot 1). Thethumbsorew E is fitted with a nut which fills the recessed portion ofthe slot 1) flush, but does not extend above the face of the jaw-piece.By loosening this thumb-screw, which is readily done from the underside, the jaw-piece may be readily adjusted on the body-piece to theextent of the slot 1), and by tightening it the parts will be firmlyheld together. With the exception of this longitudinal adjustment,

which is necessary at some point between the upper and lower jaw piecesof dental articulators, the body-piece A and the upper-jaw piece 13practically form a single part, and I consider them as constituting theupper member of my articulator. By providing for this longitudinaladjustment of the upper and lower jaw pieces in other Ways known to theart the body-piece and upper-jaw piece might be made in one integralpart; but I prefer to construct them of two parts, as herein described.

To support the thumb-screwH,which regulates the distance the jaw-piecesare held apart, I form a pyramidal-shaped frame I on the inner centralpart of the base of the lowerjaw piece toward its rear end and mount thethumb-screw in the upper end of this frame. Hitherto this support hasbeen a bar extended across the frame of the articulator or a bracketformed thereon. These bars or brackets are more or less in the way, butwith my pyramidal or cone shaped support extended up from the innercentral part of the base of the lowerjaw piece there is but little morespace occupied than is required for the thumb-screw alone, and there isnothing to impede the sweep of the fingers of the operator around it.

The hinge or joint between the body-piece and lower jaw piece is formedby the upwardly-extending arms 61 terminating in ballshaped ends whichturn in sockets formed on the under edges of the body-piece at e. In therear of these sockets the side portions of the body-piece are formedwith recesses which are surrounded by walls g. A perforation is made inthe center of each socket through the wall separating it from the end ofthe recess.

A slot is cut in the ball ends of the arms (1, and rods or strips ofmetal are secured therein by pins passed laterally through them and theball ends, so as to form a jointed connection. These connecting rods orstrips are passed through the perforations in the walls of the socketsand are then encircled by coiled springs f, which are secured thereon bynuts on the ends of the rods, as shown in Figs. 3 and 4, Fig. 4 being aninverted longitudinal section of one of the side portions of thebody-piece A. By this arrangement the ball ends of the arms (I aresecurely held in the center of the sockets at e by the tension of thesprings f, and the lower-jaw piece 0 is securely hinged to thebody-piece A and by it to the upper-j aw piece B. The ball ends willalways turn snugly in the sockets, and will thus prevent the loosenessof ordinary joints which may be caused by wear or by careless fitting.

The spring connections will permit either one or both of the ball endsto be drawn a little away from their sockets, so as to produce a lateralor grinding movement of the jaw-pieces, as in masticating, oraprotruding movement of the lower-jaw piece, as in incising.

I do not wish it understood that I restrict myself to the preciseconstruction herein described, as I desire to avail myself of theequivalents permitted by law.

lVhat I claim as new, and desire to secure by Letters Patent, is-- 1.The combination of upper and lower members hinged together ata pointabove the base of the lower member, and at approximately an equaldistance from the rear end of the upper member, the rear ends of themembers-being adapted to come in contact when the articulator is opened,and to hold the members at approximately right angles with each other,substantially as described.

2. In dental articulators, the combination of an upper member havingspherical-shaped sockets set at an angle of substantially fortyfivedegrees on the under sides of its body, a lower member having armsprojecting into said sockets and having ball-shaped ends adapted to turntherein, and means to adj ustably connect the parts together,substantially as described.

3. The combination of abody-picce having rearwardly-extended sideportions, a lowerjaw piece having upwardly-extending ends adapted to fitin sockets in the side portions of the body-piece and hinge therein,pins jointed to said ends and passed through the walls of said sockets,and springs encircling said pins so as to draw the ends of the jawpieceinto the sockets, substantially as described.

In witness whereof I have hereunto set my hand in presence of twowitnesses.

FRANK FO URT.

